signal-desktop/ts/util/whitespaceStringUtil.ts

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2022-01-26 21:58:00 +00:00
// Copyright 2022 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
const WHITESPACE = new Set([
' ',
'\u200E', // left-to-right mark
'\u200F', // right-to-left mark
'\u2007', // figure space
'\u200B', // zero-width space
'\u2800', // braille blank
]);
export function trim(str: string): string {
let start = 0;
let end = str.length - 1;
for (start; start < str.length; start += 1) {
const char = str[start];
if (!WHITESPACE.has(char)) {
break;
}
}
for (end; end > 0; end -= 1) {
const char = str[end];
if (!WHITESPACE.has(char)) {
break;
}
}
if (start > 0 || end < str.length - 1) {
return str.substring(start, end + 1);
}
return str;
}
export function isWhitespace(str: string): boolean {
for (let i = 0; i < str.length; i += 1) {
const char = str[i];
if (!WHITESPACE.has(char)) {
return false;
}
}
return true;
}